Switching mechanism



T. B. FEYON SWITCHING MECHANISM Filed Oct. 23, 1922 Apr. 24,1923.

2/ Z mu m Patented Apr. 24, 1923.

n-rrso srrss TRACY B. RYON, OF WALTHAM, MASSACHUSETTS.

sweet-me MnonAnIsM.

Application filed October 23, 1922. Serial No. 596,209.

To (ZZZ whom 2'25 ma concern:

Be it known that I, TRACY B.' RYoN, a citizen of the United States,residing at lValtham, in the county of Middlesex and State ofMassachusetts, have invented a new and useful Switching Mechanism, ofwhich the following is a specification.

This invention relates to mechanism for shifting or switching trackmembers of the type used in overhead industrial conveyor systems. Suchsystems are used for many purposes and very commonly for conveyingmolten iron to the diiferent parts of a foundry. In very large plants itis the present practice to provide motor driven cars or p opeller theswitching of the cars be ng controlled by the attendant or from acentral control station. The switching mech anism heretofore used forsuch purposeshas often proved defective and unsatisfactory, particularlyby failure to properly align the track sections in their differentoperative positions.

"It is the general objectof my invention to provide improved mechanismfor this purpose, by which reliable and eiiicient operation is assuredand by which accurate alignment of the track sections is attained.

In the attainment of this general object,

an important feature of invention relates to the provision of a yieldingor frictio'nal connection between the 'movable tra cl'r sections and theactuating mechanism therefor.

My invention further relates to a construction by which binding orwedging of the actuating shaft is avoided and to other arrangements andcombinations of parts which will be hereinafter described and moreparticularly pointed out in the appended claims. i

A preferred form ofmy invention is shown in the drawings, in which I IFig. 1 is a plan View of improved switching mechanism;

Fig. 2 is an end elevation thereof ;1

Fig. 3 is a detail sectional view'of the friction connection between theactuating shaft and its driving gear; H

V Fig. 4 is an end elevation of the shaft and the adjusting nut thereon;and I Fig. 5 is an enlarged detail elevation of thecircuit reversingmechanism.

Referring to the drawings, I have shown portions of an overhead conveyorsystem comprising fixed track members 11 and 12, a straight movabletrack section 13' and a curved movable track section 14. The sections 13and let are rigidly connected by cross bars 15 and are movable as a unitto align either the section 13 or the section 14 with the track member10. The section 13, when thus aligned, connects the track member 10 withthe straight track member 11 and the section 14 when in operativeposition connects the track member 10 with the curved track member 12.

A threaded nut 16 is mounted between the cross bars 15 and is a runningfit for a threaded actuating shaft. 17 rotatable in bearings in fixedframe members 18 and 19. A motor 20 is connected through a pinion 21 andgear 22 to the shaft 17 and is also connected from the gear 22 through agear 23, pinion 2 1 and gear 25 to a shaft 26 on which is mounted acircuit reversing arm 27,-the shaft 26 being rotatable in a fixed framemember 28. s

A contact arm 30 is mounted on a pivot 31 and is continuously connectedto one line wire 32 of the motor 20. l/Vires 33 and 34: are connected atone end to fixed contact points 35 and 36 with which the contact arm 30is adapted to engage and at the other end to reversed series field coils37 and 38. p Tlie field coils 37 and 38 are connected to the contacts 39and 40 of a starting switch 41 connected through a wire 42 to one of themotor brushes 43. The second brush 44 is permanently connected through awire 45 to the second line wire 16. The electrical connections describedare illustrative only and in themeselves, form no part of my invention.The switch 41 may be manu'algiy, mechanically or magnetically actu-' ateAn additional arm 17 is mounted on the pivot 31 and the upper end ofthis arm eX tends into the path of movement of the re versing arm 27. Aspring 48 (Fig. 5) yield ingly connects the outer ends of the arms 30and 37.

\Vhen the parts are positioned as shown in Fig. 5, the feed wire 32 isconnected to the motor 20 through the contact 36 and the wire 34. If thereversing arm 17 is now rotated in the-direction of the arrow a, the arm27 will eventually engage the arm 47, forcing it to the right in Fig. 5until the spring 48 passes the axis of the pivot 31. The spring willthen act to move the arms 30 and 47 quickly to the position shown indotted lines in Fig. 5, thus breaking and reversing the motor circuitand connecting the feed wire 32 to the motor through the contact 35 andthe wire 33. When the circuit is thereafter manually closed through thewire 33, the motor will be started in the reverse direction and the arm27 will swing around to engage the opposite side of the arm 47 and throwit from the dotted to the full line position in Fig. 5, thus restoringthe original onnections. It will thus be seen that each time that themotor is started, it will operate to give the shaft 26 approximately onesingle revolution, after which the motor will be stopped and itselectrical connections will be reversed.

The gear 22 is yieldingly connected to the shaft 17 by the frictiondevices shown in Fig. 3. A sleeve 50 is keyed to the shaft 17 and thegear 22 is rotatably mounted on this sleeve. One end of the gear isrecessed to receive a friction ring 51 and also a flange 52 on the endof the sleeve 50. At its opposite end the gear 22 is similarly recessedto receive a friction ring 53 and a collar 54 keyed to the sleeve 50 andslidable thereon. The outer end of the sleeve 50 is threaded to re ceivea nut 55 and a spring washer 56 is interposed between the nut 55 and thecollar 54:.

The friction between the gear 22 and shaft 17 can be regulated byadjusting the nut 55 on the sleeve 50. I have shown the nut as having aslot 57 at one side and having a locking screw 58 by which it may befirmly clamped in position.

The motor 20 is thus frictionally or yieldvingly connected to the shaft17 through the gear 20 but is positively connected to the reverse arm27. The shaft 17 is also provided with flexible spring washers 60(Fig. 1) and collars 61 on each side of its bearing in the frame member18, these spring washers being provided for a purpose to be described.

Stops 62 on the track section 13 act to operatively position the section13 when the stops engage the track members 10 and 11. Stops 63 on thesection 14 similarly align this section with the track members 10 and12.

Having thus described my invention, the method of operation is asfollows:

Assuming the parts to be in the position shown in Fig. 1., after theoperator has moved the starting switch 41 to the contact 10, the motorwill at once rotate the threaded shaft 17 in such a direction as toshift the track sections 13 and 14: from the full line to the dottedline position in Fig. 1, bringing the section 14 into operativeposition. When this position is reached, the stops 63 will engage thetrack members 10 and 12, preventing further movement of the section 14.The motor 12, however, will continue to revolve, such action beingpermitted by the frictional yielding connection between the gear 22 andthe shaft 17. The motor will thus continue in operation until the arm 27has engaged the arm 47 and reversed the position of the arms 47 and 30,breaking the motor circuit and reversing the series field coilconnections and 36.

To restore the track sections to their initial relations, the switch 41is thrown from the contact d0 to the contact 39, thus completing thecircuit through the reverse field coil 37 and causing the motor torevolve the shaft 17 in the opposite direction.

The spring washers 6O permit a slight yielding movement of the shaft 17as the stops 63 are engaged, thus cushioning the shaft and preventing itfrom becoming wedged too tightly in the nut 16. With this constructionthe shaft 17 is more easily started in the reverse direction than wouldbe the case with a positive thrust bearing.

The operative position and alignment of the track sections is thusdetermined entirely by the rigid stops 62 and 63 and is not dependentupon the stopping the motor 20 at some predetermined point, as has beenheretofore attempted.

Having thus described my invention and the advantages thereof, 1 do notwish to be limited to the details herein disclosed otherwise than as setforth in the claims, but what I claim is 1. A switching mechanismcomprising a pair of track sections, means to shift said sectionsalternatively to operative positive position, positioning devices forsaid sections, driving mechanism for said shifting means, effective tomove said track sections against one or the other of said positivepositioning devices and means thereafter engaged by the continuedoperation of said driving mechanism effective to stop said mechanism.

2. A switching mechanism comprising a pair of track sections, means toshift said sections alternately in opposite directions, said meansincluding a motor, a circuit controlling switch for said motor, positivedriving connections between said motor and said circuit controllingswitch, and yielding driving connections between said motor and saidtrack sections.

3. A switching mechanism comprising a pair of track sections, means toshift said sections as a unit to operatively position said sectionsalternately, driving mechanism for said means, means to limit suchshifting movement, a yielding device permitting said driving mechanismto over-run its positioning operation, and controlling means becommgoperative during such over-run to stop said driving mechanism.

at. A switching mechanism comprising a pair of track sections, means toshift said sections as a unit to operatively position said sectionsalternately, driving mechanism for said means including a reversiblemotor, a device permitting said motor to over-run its positioningmovement, and means to stop said motor during such over-run after apredetermined period of operation and independent of the movement andposition of said track sections.

5. A switchingmechanism comprising a pair of track sections, means toshift said sections as a unit to operatively position said sectionsalternately, driving mechanism for said means including a reversiblemotor, a

device permitting said motor to 0ver-run its positioning movement, andmeans to stop said motor during such over-run after a predeterminedperiod of operation and independent of the movement and position of saidtrack sections and to simultaneously reverse the circuit connectionsthereof.

6. A switching mechanism comprising a pair of track sections, a threadedshaft connected to shift said sections, stops to operatively positionsaid sections, driving means for said shaft, a yielding connectionbetween said driving means and said shaft, and means to yieldinglyposition said shaft axially.

In testimony whereof I have hereunto afiixed my signature.

TRACY B. RYON.

